<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>伪类选择器</title>
    <style>
        a:hover {
            color: red;
        }
    </style>
</head>
<body>
    <!-- 鼠标悬停状态 选择器：hover -->
     <a href="#">鼠标悬停</a>
</body>
</html>